Electric lamp or the like



July 22, 1947,

J. w. FULTON ET AL 2,424,446

ELECTRIC LAMP OR THE LIKE .Fil'ed Oct. 10, 1942 2 Sheets-Sheet l John\rFul't'on Al'ton .Foote,

Their Attorneg.

ELECTRIC LAMP OR THE LIKE Filed Oct. 10, 1942 2 Sheets-Sheet 2 lnven'tors JohnWFuHon, Altoh G.Foo'te,

98 b9 ,4 MW

Their A't'torney.

Pam's-ea J ly 22, 1941 l OFFICE ELECTRIC LAMP OR- THE LIKE John W.Fulton, Clevela Foote, Wickllfie,

Electric Company,

nd Heights, and Alton G. bio, assignors to General a corporation of NewYork Application Octoberl0', 1942, Serial No. 461,578 1 Claims. (01. 67-31) This invention relates to electric translation devices, and isconcerned with the envelope and base construction of such devices, andalso with holding and connecting means or sockets for them. Theinvention is'especially adaptable and advantageous for photofiash lamps,as they are called, comprising a combustible fuel charge with associatedoxidizing means and igniting means. and is explained hereinafter withparticular reference to translation devices of the photoflash type.

Photoflash lamps have heretofore been built on the general incandescentlamp model, comprising hermetic glass envelopes or bulbs equipped withbases like some of those used on small incandescent lamps. The glassbulbs used have necks into which are sealed mounts of glass stem-pressand flare construction, including lead wires between which are connectedfine bridgewires or filaments for igniting the fuel used. The fuel mayconsist of very thin aluminum foil or the like, or of finely or thelike, the bulb is filled with an' atmosphere of oxygen; while finelydivided zirconium ismixed with an oxidizing compound such as sodiumperchlorate. In the latter case, the whole ignition charge consists ofthis combustion mixture, which is coated on the current leads in contactwith the fine bridge-wire, to be heated and ignited by heating currentpassed through the latter; while when foil or wire is used, only a smallprimer or ignition charge of such combustion mixture is applied to theleads.

To protect the photoflash bulb from the possibility of being cracked andeven shattered when large or very hot particles from the flash strikeit, the bulb is internally lacquered, and sometimes externally too. Asthe presence of lacquer on the bulb neck where it is sealed to the stemwould interfere with making this seal, it is necessary to avoidhavlngthe lacquer on this portion of the bulb; and this makes theoperation oi coating the bulb with lacquer more diflicult than wouldotherwise be the case. Indeed, a considerable area at the bulb end hasto be left unlacquered, since otherwise the lacquer over a substantialzone at and near the bulb neck would be burned during the sealing-in,destroying its protective value and producing an unsightly scorchedappearance. Furthermor seal may result if particles of the ignitioncharge fall into-this seal while it is being formed by fusion of thebulb neck and the stem flare.

The present invention permits of overcoming ;hese difliculties with abulb and base construc- 21011 that is simpler and cheaper to manufacturedivided zirconium. For foil failure of the bulb neck single operation,which than those heretofore used. This construction permits of doingaway with the usual stem-press and flareby mounting the leads andbridge-wire or filament directly on the part which serves as base. Thusfusion of glass parts for sealing-in purposes is dispensed with; thesealing-in and basing operations are in effect merged into a can besimplified as compared with the former basing operation; and thefabrication of the base-attached mountcan be made a very simple matteras compared with fabricating a mount of the old stem-press and flaretype. Moreover, the lacquering of the bulb right to the very end of itsneck no longer offers any difficulties. The base itself is alsopreferably diflerent from bases heretofore used, and coacts with acorrelated novel socket. The lightcenter length of the lamp can beconsiderably shortened, as compared with prior constructions.

The use of a base structure which also forms part of the lamp envelopewall has already been suggested in various prior patents, as exemplifiedin Patents 628,973 to Wierre, 2,264,043 to Ledig and Helwig, and2,272,059 to de Margitta. These, however, are all essentially presentinvention.

Various features and advantages of my invention (besides thosementioned) will appear from the description of species and forms ofembodiment of the invention, and from the drawings.

In the drawings, Fig. 1 is a side view of a photo-flash lampconveniently embodying the present invention; Fig. 2 is a tilted view ofa corresponding socket and holder device; Fig. 3 shows an axial sectionthrough this socket and holder, with a portion of an associatedreflector, on a larger scale than Fig.2; and Fig. 4 is a fragmentary endview of one of the socket parts.

Figs. 5 and 6 are views similar to Figs. 1 and 2 illustrating somewhatdiflerent lamp and socket devices.

Figs. 7 and 8 are views similar to Figs. 1 and 2 illustrating yet othervlamp and socket constructions.

Fig. 9 is an exploded tilted view of the component parts of a mountassembly for the lamp shown in Fig. '1; Fig. 10 is a tilted viewillustrating a stage in the manufacture of this mountas sembly; Fig. 11is a side view, partly sectional, of the completed mount assembly; andFig. 12 is a side view of a corresponding lamp bulb.

Figs 13 is a plan view of an apparatus for exhausting, basing, andsealing off the lamp; and Fig. 14 shows a horizontal sectiontherethrough, taken as indicated by the line and arrows l4ll in Fig. 13.

difierent from the solves the lacquer so Fig. is a fragmentary sectionalview illustrating another form of lamp construction; and. Fig. 16 is asimilar view illustrating a stage in the fabrication of the mount shownin Fig. 15.

Fig. 1 illustrates a simple form of device constructed in accordancewith the invention. As shown, this device comprises as its envelope alight-transmitting bulb 20, of ovoid shape, having a short reducedcylindrical end or neck por- -tion 2 l, and coated-with the usualprotective lacapertures or holes 26, :26 in the base web 24, and

21, 21 are exposed at the outer side or bottom of the cap '23 as contactterminals for connecting the device in circuit. Besides ,the base cap 23and the leads 25, 25, the lamp mount M comprises a bridge-wire orfilament connected between the inner ends of the leads 25, 25. Ratherheavy deposits 3|, 31 of the combustion mixture are coated on the leadends, in direct contact with the bridge-wire 30 adjacent the leads. Thebulb 20 may have a filling of oxidizing gas at ordinaryatmosphericpressure, or lower, preferably oxygen rather than air.

As shown in Fig. 1, the bulb neck 2| and the current lead wires 25, 25are secured and sealed to the base cap 23 by means of 33 fused andadherent to all these parts, and thus sealing their joints gas-tight.The plastic 33 seals the passage of the current connections 25, 25 intothe disc or cap apertures. There may be a substantial amount of theplastic 33 fused to the interior of the base cap .23 as a thick coating,completely filling the clearance between the inside of the cap rim andthe exterior of the bulb neck 2i, extending up inside ofthe neck 2|about level with the upper edge of the rim, and also extending somedistance up each of the leads 25, 25. This ample area of union betweenthe sealing plastic 33 and the parts 23, 2|, 25, 25 is the result of thewetting and adherence of the plastic, when fused, on the materials ofthe several parts, as well as of the quantity of plastic used, andassures ample strength of the joints. The presence of the lacquercoating 22 on the glass does not impair the adhesion of the plasticthereto, since the plastic wets and adheres to the lacquer, or even asto stick directly to the glass. Accordingly, the whole interior of thebulb 20 is effectively protected against the shattering effect of heatedmatter thrown out from the flash. While the quantity of plastic. 33 isnot very critical, a volume or it about equal (after fusion) to half theinternal capacity of the cap 23 answers very well.

As shown in Fig. 1, the projecting, end portions 21, 21 of the currentconnections or lead wires 25, 25 are bent aside from the apertures 26,26 to lie against the outer side of the cap web. To prevent turning ofthe leads 25, 25 even before they are secured by the plastic 33, theseleads may be antiturningly engaged or interlocked with the cap. Toengage the ends of the leads 25, 25 for this purpose, the cap web mayhave external recesses 36, 36 which may be formed as holes their outerends organic plastic interfuses with or dis-' materials used forpiercing the web, and the lead ends may be retroverted to extend intothese recesses, as shown in Fig. 1. As also best shown in Fig. 1, theholes 26, 36, 26, 36 are arranged in that order diametrally of the cap23, one hole 36 at its center and the other near its rim 24, while theholes 26 are equidistant to either side of the center hole 36. Thus onecontact 21 is very much more edcentric than the other contact 21 withreference to the center or axis of the base 23, which allows thesecontacts to be engaged by socket contacts in any angular position of thedevice in the socket, as explained hereinafter. Preferably, the pairs ofholes 26, 36 for the two leads 25, 25 are spaced equally, so that theseleads are counterparts of one another, and interchangeable. The fusedplastic 33 fills the clearances around the leads 25, 25 in the holes 36,36, and these fused seals render the joints gas-tight, just as in thecase of the holes 26, 26, besides securing and fixing the lead endsfirmly.

The base cap 23 may preferably be molded out of thermo-setting plasticwith a suitable finely divided fibrous filler, such as aphenol-formaldehyde plastic with a filler of wood flour. The plastic ofthis character that is marketed under the name of Textolite moldingcompound 2154 gives good results; but other molding plastics may also beused, or even materials of altogether different character, such asdie-pressed sheet metal (preferably nickel-plated), or molded glass. Thelead wires 25, 25 may be of iron or other suitable metal, with theirportions outside the cap 23 preferably nickel-plated to prevent rusting.

The properties that are desirable for the sealing plastic 33 are that itshould adhere to the the base or cap 23 and the leads 25, 25, as well asto the glass or to the lacquer coating the bulb neck 2|, so as to sealthe joints gas-tight; that it should be sufficiently. flexible toaccommodate differences in thermal expansion and contraction of theseparts over the temperature range met with in fabrication, as well as inservice; that it should at the same time be sufficiently rigid attemperatures over this range to resist relative displacement of theparts, as well as gas flow through their joints under the pressuredifferences encountered in manufacture and in service; that it shouldnot be deteriorated by temporary high temperatures met with infabrication or in service, nor subject to deleterious aging at moreordinary temperatures, or by prolonged exposure to light; and that underthe relatively high temperatures of fabrication, especially, it shouldhave a low vapor tension. These requirements are in general lessrigorous for photoflash lamps than'for incandescent lamps or forelectric discharge devices.

For the method of manufacture hereinafter described, it is desirablethat the resin 33 be thermoplastic rather than thermosetting. Plasticsthat have met the requirements very satisfactorily in photofiash lampsare the vinylite acetate resins of the A" series, in the form of moldingpowder, and particularly the grade marketed as AYAF by the NationalCarbon Company.

A socket suitable for the lamp and base illustrated in Fig. l is shownin Figs. 2 and 3 as comprising a multiplicity of resiliently separableparallel fingers 40 for embracing and peripherally gripping the base 23,and also resiliently yielding contacts 4|, 42 for engaging endwiseagainst the contact portions 21, 21 of the leads 25, 25 exposed at theouter side of said base;;:The group of fingers 40 are shown as annularlyarwhen the base is pushed in amongst them. On

their inner sides just behind the bevelledends 45, Fig. 3, the fingers49 are reduced on a bevel outward to afford sloping shoulders 46 forsnapping and looking over the edge of the base 23 to retain it. Asshown, the contact 4| is a ring formed by the end convolution of ahelical wire spring mounted on the reduced end of the shoulderedinsulative part 41. This annular contact 4| is of such radius as toengage the more eccentric contact 21 in any angular position ,of thebase 23in the socket. The contact 42 is shown as the head of a pin whoseshank extends rearward through the insulation 41, and is provided with abutton-head or handle 48 behind the socket structure. This contact 42 isurged outward by a helical spring 49 acting between its head, and thebottom of a central bore in the part 41. The contact 42 is of such sizeas to engage the more central contact 21 in all possible angularpositions of the base in the socket. The contact 42 may serve as a lampejector, and its shank and the button -48 as the operator for actuatingit at the outside of the socket.

As shown in Figs. 2 and 3, the socket shell 44 is housed andaccommodated in a bore of an insulative part 59 (which may convenientlybe referred to as a holder), with its flaring mouth 45 projecting infront of said part. The rear end of the holder bore is enlarged at ashoulder 5|. The unslotted rear end of the shell 44 fits into the holderbore in front of the shoulder 5|, while the enlarged rear end of theinsulative part 41 fits into the holder bore behind and against theshoulder 5|, and is fixed and secured by any suitable means.

While any suitable means may be used for energizing the contacts 4|, 42to flash a lamp in the socket, it is convenient to mount such meanspartly on.or in the holder 50 itself. As shown in Fig. 2, the main bodyof the holder adjacent the socket shell 44 is hollow, and houses abattery of two dry cells 52, 52 which are shown oppositely arranged,each with contacts of opposite polarity at its opposite ends as usual.At one end of the battery compartment or cavity, remote from the socket,the adjacent dry cell ends (of opposite polarity) engage the ends of aresilient contact strip 53 that is centrally secured to the cavity wall,as by screws 54. At the other end of the battery compartment, one of thedry cell ends engages a contact 55 that is mounted on the cavity walland is connected by a lead 56 to the spring contact 4|, while the otherdry cell engages a contact portion ,of a metal strip connector 51 whichextends diagonally across the battery compartment and through an opening58 into one end of an adjacent wiring compartment. From thecentercontact 42 or its spring 49, a connector lead 59 extends into theother end of the wiring compartment. As shown in Figs, 3 and 4, theleads 56, 59 lie in radial slots GI, 62 in the insulating Plug Dart 41.vLampfiashing circuit leads 63, 64 which may form a suitable cable areconnected to the connectors 51, 59 in the Wiring compartment and extendout through an opening in one side thereof to any suitable switch means(not shown) for flashing bayonet pin 13 fixe distributing" the light ofthe flash is. indicated by a central fragmentary portion thereof securedto the holder 50 around the shell 44', by means of screws 66.

After the lamp has been flashed, the buttonhead 48 may be pressedforward to push the contact 42 forward and elect the lamp-from thesocket.

Fig. 5 show a form of construction in which the leads 25, 25 extendthrough the base holes 26, 26 as stout pins that terminate in conicallyundercut enlarged heads 21a, 21a outside the bottom of the base 23. Asshown, these contacts 21a, 21a are symmetrically located at oppositesides of the axis of the base 231;, the holes 36, 36 of Fig. 1 beingomitted. The enlargement of the conical heads 21a, 21a outside the basecap 23a assists the fused seals or joints at 26, 26 in resisting inwarddisplacement of the leads 25, 25 through the base 23a. While this devicemay be used'in a socket essentially like that shown in.

Fig. 2, the undercutting of the contact heads 21a, 21a adapts them fordirectly retaining the device in a socket, besides making the electricalconnections. For this purpose, Fig. 6 illustrates a device comprising abayonet socket 19 on an Edison screw plug 1|. In .the bayonet socket 19is an adapter shell 12 that is secured by external (1 in the shell 12,and is provided with resilient contact and securing members 14, 14 forinterlocking engagement with the base contact heads 21a, 21a when thebase 23 is inserted in the socket 19 far enough to bottom against theshoulder afforded by the edge of the shell 12. A shown, the contacts 14,14 consist of staple-like springy wires having their ends insulativelyfixed to the bottom of the adapter shell 12, while their intermediateportions extend eccentrically (like chords) part way across the interiorof the shell 12, and are oppositely notched or bowed apart at 15, 15.When the base 23a is inserted in the socket 19 as above mentioned, theconical contact heads 21a,21a lie between the members 14, 14; and whenthe lampis then turned about 90 either way, the heads 21a, 21a bend theresilient members 14, 14 apart and then snap into the notches 15, 15.When this happens, the contact heads 21a, 21a interlock behind andbetween the member 14, 14, which thus hold the lamp firmly fixed in thesocket.

As shown in Fig. 6, there is a separate ejector and operator forejecting the lamp from the socket 10, consisting of a lever 16 that isfulcrumed on an axis 11 in a block attached to the socket 19 and extendsthrough slots in said block and in the socket wall to the center of thesocket, where it has a head '18 for engaging the bottom of the base 23directly between the contact heads 21a, 21a. 0n the outer end of thelever 16 is shown a handle knob 19. By pressing down on this handle 19,the inner lever-end 18 is pressed up against the base 23 to lift it outof the socket 10, and the member 14, 14 are concurrently forced apart bythe sloping surfaces of the heads 21a, 21a to release these heads- Fig.7 shows a form of construction in which i the leads 25, 25 extendthrough the base holes a lamp in the socket shell 44, when desired. A

sheet metal reflector 65 for suitably directing and 26b, 26b as stoutpins whose outer ends form straight cylindrical contacts 21b, 21b ofuniform size, which are symmetrically located at opposite sides of theaxis of the base 231), the holes 36, 36 of Fig. 1 being omitted. Thereduction in size of the contacts 21b, 21b occur at-shoulders 86, whichabut against corresponding shoulders formed by reductionof the baseholes 26b, 26b

tions.

and assist the fused seals or joints in resisting inward displacement ofthe members 21b, 21b through the base 23b. For this type of base 23b. avery simple socket is shown in Fig. 8, comprising an insulative member8| whose recessed end receives the base- 23b and has openings at thebottom of the recess in which are mounted resilient contact clamps 14b,14b that receive and grip the contact pins 21b, 21b. This socket 8| mayhave an Edison screw plug (not shown) similar to that in Fig. 6.

. There are now to be described more fully the component parts and thefabrication of the mount illustrated in Fig. 1, and also the sealing inof this mount into ,a bulb 28 and the related opera- This descriptionwill enable those skilled in the art to carryout the correspondingoperations for the modified devices illustrated in Figs. and 7' veryeasily.

As shown in Fig. 9, the principal components of the mount are the basecap 23 and the lead wires 25, 25. The cap disc 23 is shown as hollowedout to a shallow cup or pan with a relatively thick bottom wall or webthat is further thickened locally as indicated by an internal fiattoppedannular ridge 83. In other Words, the end disc 23 is annularly groovedaround the central protuberance or ridge 83 to accommodate the envelopeend or neck2I. tend through the thickness of the ridge 83, beingsymmetrically located with respect to the center or axis of the cap,where it is relatively thin and has the central hole 36. The other hole36 is shown in the relatively thin zone of the cap bottom around theridge 83. The location of the lead-hole 26, 26 in the augmentedthickness of the cap bottom at the ridge 83 affords ample bore lengthsaround the leads 25, 25, while the ridge edges are favorable for theadherents of the sealing plastic. The base cap 23 may be molded out ofthermo-setting plastic, such as Bakelite, or Textolite molding compound2154; or it may wood impregnated with thermo-setting synthetic resin orplastic, such as Bakelite; or it may even be of molded glass or othermaterial.

Prior to insertion into the base-cap 23, the leads 25, 25 may have theirlower ends bent into right-angled hooks 21, 21 like those in Fig. 9. Asshown, the lower portions of these leads 25, 25 are thicker, and may beof nickel-plated iron wire, while the upper portions, which are thinnerwires butt-welded to the lower portions, may be of unplated iron. Afterinserting the lead wires 25, 25 through the cap holes 26, 26 andinserting their ends into the cap holes 36, 36, these parts may bepermanently secured and sealed together 'with thermoplastic asillustrated in Fig. 10. For this purpose, the assembly may be placed ina conformable socket depression of a multisocketed refractory plate 86(made of an asbestos and cement composition), and the base cap 23 may becharged with sealing plastic 33 such as vinylite resin A, in its usualcommercial form of molding powder, about level with the top edge of thecap. The other sockets of the plate 86 having been similarly loaded, theloaded plate may be placed in an electrically heated oven (not shown)and kept at a temperature sufficient to fuse the resin- (e. g., about170 C.) for about 12 hours, so as to degas the resin thoroughly, afterwhich the heating current may be shut off and the oven and its contentsallowed to cool. After cooling, the thin upper portion of the leads 25,25 may be bent closer together, .a tungsten filament 38 may be weldedacross them, and the joints may The lead-holes 26, 26 exbe coated withdeposits 3|, 3| of the combustion mixture above referred to, all asheretofore usually done in the manufacture of photofiash lamps. Theresult is the completed mount M as shown in Fig. 11.

The bulb 28 shown in Fig. 12 having previously been coated inside andout with lacquer 22 (such as above indicated) right down to the bottomedge of itsneck 2|, by methods well understood in the art, the lamp maybe completed by assembling the lacquered bulb with the amount M,exhausting the bulb and charging it with the desired gaseous atmosphere,and re-fusing the plastic 33 in the cap 23 and forcing the bulb neck 2|into it against the bottom of the cap, thus sealing in the mount andsealing off the lamp. It is convenient to do I the necessary heating ofthe'parts preliminarily and separately; by placing the mount cap 23 andthe bulb neck 2| is socketed metal heating plates (not shown) somewhatsimilar to the plate 66, Fig. 10, preferably electrically heated. Themount cap 23 may be heated to about 170 C., as before, and the bulb neck2| some 15 to 20 hotter. Only a brief heating of about 1 minutes isnecessary.

For the exhausting, gas-charging, and actual sealing operations may beused an apparatus comprising a hollow metal exhaust head or block 98having an'upward-open mouth lipped with an elastic (rubber) sealing ring9|, and having in its internal cavity a thermoinsulative socket piece.

92 (as of molded asbestos composition) to receive the mount base 23. Asshown, the socket 92 is mounted on the upper end of an upright rod 93that is longitudinally movable (vacuum and fluid-tight) through anelastic packing 94 at the bottom of the head 98, and may be operated toshift the socket up and down by means of a lever 95 fulcrumed at 96 on asupport extending downward from the head, and having a pin and slotconnection 98 to the lower end of the rod 93. At an intermediate levelin the interior of the exhaust head 98, there may be provided analigning guide I88 for the neck 2| of a bulb 28 inserted neck-down intothe exhaust head mouth and seated on its sealing lip 9|, which makes afluid-tight seal with the lower portion of the bulb. As shown in Figs.13 and 14, this guide I88 has a circular opening of a normal sizeconformable to the bulb neck 2|, but is expansible to a sufllcientdiameter to pass the base cap 23 when the latter is inserted in thesocket 92 or removed. For this purpose, the bulb-neck engaging portionof the guide I88 is divided into a number of armate segments carried byflat spring fingers I82 extending inward from a ring I83 adjacent theinternal circumference of the exhaust head 98. Thus constructed, theguide I88 can readily be stamped out of springy sheet metal. As shown,the ring I83 rests on internal shoulders I84 of a split liner I85 in thecavity of the head 98, adjacent the upper edge of this liner, and isheld in place by an upper split liner I86 resting on its outer margin. Agas duct i88 opens into one side of the head 98, and may be connectedand shut off at pleasure to and from either a highvacuum exhaust system,or a supply of desired gas (such as oxygen) at about atmosphericpressure or lower, by any suitable valve and conduii means, not shown.

When the bulb neck 2| and the mount cap 23 have been suitably heated, asdescribed above the thermoinsulative socket 92 is raised sufiieiently todeflect the guide fingers I82 upward and force the guide segments I88apart, allowing the cap 23 of a mount M to be placed in the socket. Thesocket 92 is depressed again to its position in Fig. 14, and a bulb 20is placed in the exhaust head 9|] with its neck 2| in the guide Hill inalignment with the opening of the cap 23. The duct I08 is firstconnected to exhaust to draw the air out of the bulb 20, and then to thegas supply to. charge the bulb with oxygen,

for example; and these connections may be interchanged as often asnecessary to wash out the bulb 20 thoroughly and to charge it with thegas in asuificiently pure state. Then the socket 92 may be raised topush the base cap 23' up around the bulb neck 2| until the latterbottoms in the cap and is sealed therein by the softened plastic 33.When the parts have cooled sulficiently to set the plastic 33, and theduct I08 has been opened to the atmosphere so as to equalize pressure onthe bulb 20, the completed lamp may be removed, the'socket 92 beingpreferably raised to expand the guide I and obviate any resistance whichit might offer to passage of the base-cap 23 therethrough.

Figs. and 16 illustrate another particular form of lamp constructionandtits manufacture, comprising a base 230 with pinficontact terminals21c, 21c, adapted for use in a. socket generally similar to thatillustrated in Fig. 8.

The bulb 20 shown in Fig. 15 may be like that already described, and maybe similarly coated with protective lacquer 22. The base cap 230 isshown as of slightly different form, and may be fabricated out of sheetmetal by die-pressing: it may preferably be made of soft iron or mildsteel about 0.03 inch thick. Its bottom web 240 is shown reverselycupped, with an annular round-bottomed groove |l0 therein adapted totake the edge of the bulb neck 2| with ample clearance, inside as wellas outside. Within the groove, the web 240 has a pair of holes 260, 2%(Fig. 16) for the stout contact terminal pins 21c, 21c forming the lower,ends of the current 'leads 25c, 250, these holes being large enough toafford ample clearance around the pins. The leads 25c, 250 may be fixedin the cap holes 260, 26c and insulated from the cap by meansofinsulative cementing material Ill, preferably vitreous, which mayconsist of enamel glass fused around the leads and to the cap web 240 inand around the openings 26c, 260. The seals for the two holes 260, 260are shown as merged inside the cap 230 into a single vitreous mass Ill.The bulb neck 2| is secured to the base cap 230 by means of organicplastic 33c fused and adherent to these parts, and shown as also coatingover the vitreous mass Ill and fused and adherent to the leads 25c, 250at the inside of this mass. The fused vitreous seals at attach the leads25c, 25c firmly and rigidly to the cap 230, and may also seal themtherethrough gas and Vacuum tight; but any want of hermetic tightness ofthe vitreous joints can be remedied by applying the plastic 33c so as tocoat over the vitreous mass and adhere to th leads 25c, 25c, as shown.

In manufacture, the leads 25c, 250 may each be coated with a vitreousbead ||2 fused therearound, and may then be placed in the holes 260, 260as shown in Fig. 16 and fixed by fusing down these beads to form theseal III of Fig. 15 while the leads are both suitably held in properrelation to the cap 230, out of contact therewith. After completing ther'nount M and fusing the plastic 33c into the cap 230 substantially asalready described in connection with Fig. 10, the bulb neck 2| may besealed into the base cap i x 10, i 230 (as shown in Fig. 15) and thelamp completed, all substantially connection with Figs. 13 and 14.

In order to dispense with repetitive description, various parts andfeatures in Figs. 5, 7, 15, and 16 are marked with the same referencenumerals as. the corresponding ones in Figs. 1, 9, and 11, adistinctiveletter being added where such distinction appears necessary.

What we claim as new and desirekto secure by Letters Patent of theUnited States is:

1. In an electrical device, the combination with an envelope having anotherwise open end, of a one-piece cup-shaped base of insulatingmaterialcircumposed about the envelope end, and having a plurality ofapertures in its bottom wall; current connections for electrictranslation means in the envelope extending through said apertures andthe outer side of the base as contact terminals; and a coating of vinylacetate in the interior of said base fused and adherent thereto and tosaid envelope end and current connections, thus securing the base to theenvelope and sealing the passage of the current connections into thebase apertures.

2. In an electric photoflash lamp, the combina tion with an envelopeinternally coated with adherent shatter-preventivelacquer and having anotherwise open end and containing a charge of combustible flash-emittingmaterial, of a onepiece cup-shaped base on the envelope end having aplurality of apertures in its bottom wall; current leads for electrictranslation means inthe envelope extending through the said aperturesand having end portions exposed at the outer side of the base as contactterminals; and a coating of organic plastic fused andadherent to theinteriorof said base and to said leads and said envelope end and alsomerging with the aforesaid lacquer therein, whereby the envelope isfully protected from shattering due to impact of heated matter from theflash. i

3. A mount for an electrical device having an envelope with an otherwiseopen end, said mount comprising a one-piece cup-shaped base ofinsulating material for said open envelope end having a plurality ofapertures in its bottom wall; electric translation means with currentleads therefor extending through the said apertures and having endportions exposed at the outer side of the base as contact terminals, andembodyin'g shoulders externally engaging against the base to preventinward displacement of the leads through the base; and a coating oforganic plastic fused and adherent to the interior of said base and tosaid leads, and forming fused seals securing said leads in the baseapertures and constituting the sole attachment of said leads to saidbase. A

4.. A mount for an electrical device having an envelope with anotherwise open end, said mount comprising a cup-shaped base ofinsulating material for said open envelope end having a plurality ofapertures in its bottom'wall, and also having recesses therein adjacentthe apertures; electric translation -means with current leads thereforextending through the said apertures and bent aside and laterallyexposed at the outer side of the base as contact terminals, and alsohaving their ends engaged in the recesses aforeas already described inhaving end portions exposed at latter to the base and sealing up thebase apertures.

5. A mount for an electrical device having an envelope with an otherwiseopen end, said mount comprising a cup-shaped base of insulating materialfor said open envelope end having pairs of holes through its bottomwall; electric translation means with current leads therefor eachextending out through one hole of each pair and retroverted back intothe other hole of the pair, and thereby locked against turning relativeto the base, with the portions between holes exposed at the outer sideof the base as contact terminals; and a coating of vinyl acetate fusedand adherent to the interior of said base and to said leads, and

forming fused seals securing-the latter to the base and sealing up theaforesaid holes.

6. A mount for an electrical device having an envelope with an otherwiseopen end, said mount comprising a one-piece cup-shaped base ofinsulating material circumposed about the envelope end, and having aplurality of apertures in its bottom wall; electric translation meanswith current leads therefor extending through said apertures and havingundercut ends projecting at the outer side of the base as contactterminals; and a coating of organic plastic in the interior of said basefused and adherent thereto and to said leads, and forming fused sealssecuring said leads in the base apertures and constituting the soleattachment of said leads to said base.

7. .In an electrical device, the combination with an envelope having anotherwise open end, of a one-piece cup-shaped base of insulatingmaterial circumposed about the envelope end, and

' having a plurality of apertures in its bottom wall; currentconnections for electric translation means in the envelope extendingthrough said 12 apertures and having end portions exposed at theouterside of the base as contact terminals: and a coating of organicplastic in the interior of said base fused and adherent thereto and tosaid envelope end and current connections, thus securing the base to theenvelope and sealing the passage of the current connections into thebase apertures.

JOHN W. FULTON. ALTON G. FOOTE.

REFERENCES CITED The following references are of record in the file ofthis patent:

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